Hubble sinks in the low-redshift swampland

Abstract

The cosmological standard model ($\mathrm{\ensuremath{\Lambda}}$CDM) has recently come under pressure from measurements of the Hubble constant ${H}_{0}$, and theoretically from the swampland conjecture that emphasizes consistency with quantum gravity. The authors sweep through the typical class of string theory motivated dark-energy models, (coupled) quintessence with a clever expansion in low redshift and show that these models worsen the ${H}_{0}$ tension, but they also point to a gateway that might be tested with future $21c\phantom{\rule{0}{0ex}}m$ observations.

Topics & Concepts